InvestigaciónArtículos, ponencias, comunicaciones.http://hdl.handle.net/10578/82019-01-22T00:44:47Z2019-01-22T00:44:47ZA fast and simple FIA-chemiluminescence method for the evaluationof Roselle flowers as scavenger of the free radicals generated by UVirradiated antibioticsGarcía Bermejo, Luisa FernandaMurillo Pulgarin, Jose AntonioCarrasquero Durán, Armandohttp://hdl.handle.net/10578/196912019-01-19T02:46:44Z2019-02-05T00:00:00ZA fast and simple FIA-chemiluminescence method for the evaluationof Roselle flowers as scavenger of the free radicals generated by UVirradiated antibiotics
García Bermejo, Luisa Fernanda; Murillo Pulgarin, Jose Antonio; Carrasquero Durán, Armando
This work proposes a new method for the in vitro evaluation of the effect of UV irradiation on the production of free radicals and other reactive species during the photodecomposition of drugs. The method was based on the UV irradiation of antibiotics molecules to generate excited states that undergo to homolytic bond cleavages. These reactive species can be detected by their ability to oxidize the luminol, producing the electronically excited aminophtalate, which decays to the ground state releasing electromagnetic radiation in the visible zone of the spectrum. This method was applied to penicillin G, nafcillin, azlocillin and neomycin dissolved in water. It was found that the intensity of the luminol chemiluminescence emission (CL) was proportional to the concentration and dependent on the molecular structure of these drugs. Under the optimized conditions, it was found that penicillin and azlocillin were the most susceptible to photodegradation, while neomycin sulfate was the less affected by the UV light. It was observed that the addition to the antibiotics dissolutions of a hydro-alcoholic extract of petals of calyxes of Roselle reduced the CL intensity, indicating that the extract was able to scavenge the free radicals in the irradiated drugs. This result suggest that its addition to the antibiotics can help in the protection against the radicals formed during the exposition to solar light of patients treated with topic similar antibiotics.
2019-02-05T00:00:00ZMechanical-Diode based Ultrasonic Atomic Force MicroscopiesCuberes Montserrat, María Teresahttp://hdl.handle.net/10578/196792019-01-18T02:25:09Z2009-01-01T00:00:00ZMechanical-Diode based Ultrasonic Atomic Force Microscopies
Cuberes Montserrat, María Teresa
Recent advances in mechanical diode-based ultrasonic force microscopy techniques are reviewed. The potential of Ultrasonic Force Microscopy (UFM) for the study of material elastic properties is explained in detail. Advantages of the application of UFM in nanofabrication are discussed. Mechanical-Diode Ultrasonic Friction Force Microscopy (MD-UFFM) is introduced, and compared with Lateral Acoustic Force Microscopy (LAFM) and Torsional Resonance (TR) – Atomic Force Microscopy (AFM). MD-UFFM provides a new method for the study of shear elasticity, viscoelasticity, and tribological properties on the nanoscale. The excitation of beats at nanocontacts and the implementation of Heterodyne Force Microscopy (HFM) are described. HFM introduces a very interesting procedure to take advantage of the time resolution inherent in high-frequency actuation.
2009-01-01T00:00:00ZUltrasonic nanofabrication with an atomic force microscopeCuberes Montserrat, María Teresahttp://hdl.handle.net/10578/196782019-01-18T02:35:14Z2007-11-01T00:00:00ZUltrasonic nanofabrication with an atomic force microscope
Cuberes Montserrat, María Teresa
Ultrasonic AFM may improve fabrication technologies on the nanometer scale. In the presence of ultrasonic vibration, hard surfaces can be indented and scratched with the tip of a soft cantilever, due to its inertia. Ultrasound reduces or even eliminates friction, and hence modifies the tip-nanoparticle-surface interactions in AFM manipulation. The subsurface sensitivity of the technique makes feasible the purposed manipulation of subsurface nanoscale features by ultrasonic actuation.
2007-11-01T00:00:00ZIntimations of immortality and omniscience in early childhoodGiménez-Dasí, MartaGuerrero Moreno, SilviaHarris, Paul L.http://hdl.handle.net/10578/196772019-01-18T02:24:52Z2005-01-01T00:00:00ZIntimations of immortality and omniscience in early childhood
Giménez-Dasí, Marta; Guerrero Moreno, Silvia; Harris, Paul L.
Children aged three, four and five years, drawn equally from one secular and
one religious school in Spain, were questioned about the psychological and
biological constraints that apply to two different types of person: an ordinary
human being (their best friend) and an extraordinary being (God). Children
were asked to assess whether: (1) the knowledge available to either being is
constrained by perceptual processes and (2) the life cycle of either being is
constrained by biological processes. Three year olds provided few signs of
distinguishing between the two types of being. Five year olds, on the other
hand, were quite systematic in their differentiation. They judged that the
knowledge available to a friend—but not to God—would be constrained by
the need for perceptual access and they judged that the life cycle of a friend—
but not that of God—would be constrained by the biological processes of
birth, growth and death. Implications for current accounts of children’s
conceptual development are discussed.
2005-01-01T00:00:00Z